Software QA 101: The Basics of Testing

The testing phase of software development often gets short shrift by developers and IT managers. Yet testing is the only way to determine whether an application will function properly before it is deployed. In this article, Sue Hildreth offers an overview of the why and how of software testing.

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Although it doesn't get a lot of press, testing is arguably the most
important phase in any software development project. Certainly testing is the
bestthe onlyway to know whether your project or product is destined
for success or doomed to failure before it goes live. The U.S. Commerce
Department has estimated that buggy software costs nearly $60 billion annually,
and that at least $22.2 billion worth of those bugs could have been prevented
with more thorough testing.

And although you might like to think that your newly coded application is
virtually bug-free, we all know by now that it just ain't so. Sandra Tise
of Empirix, a testing tool
maker, notes that there's simply no such thing as an error-free
application: "Frankly, I know of no software test that I've done that
has come back perfect."

There are many, many different ways to test software, but most tend to fall
into two broad categories: functional testing and performance testing.

Functional Testing

Functional testing covers how well the system executes the functions it is
supposed to executeincluding user commands, data manipulation, searches
and business processes, user screens, and integrations. Functional testing
covers the obvious surface type of functions, as well as the back-end operations
(such as security and how upgrades affect the system).

"If you have an old Vantive [CRM] system, and you have to migrate all
your information to a new [CRM] system, that is where a lot of the functional
issues will occur. You have to do that migration and then verify that the
information is there [in the new system]."

Although functional testing is often done toward the end of the development
cycle, it canand should, say expertsbe started much earlier.
Individual components and processes can be tested early on, even before
it's possible to do functional testing on the entire system.

The Aberdeen Group, a Boston-based analyst firm, has noted that because
today's applications require constant updating and redeployment, IT needs
to think in terms of testing throughout the entire life-cycle of an application.
In a 2003 InSight report, it noted that

"...cross-lifecycle software testing has a significant positive impact,
not only on software quality but also on timely application delivery and ongoing
maintenance costs, especially when it is integrated early in the application
development cycle."